Question

I have my maths exam on Tuesday and cannot remember how to do trigonometric identities at all. I was so sure, but now I'm not. I asked a similar question earlier, but I still don't quite understand. Please give me step-by-step instructions?

[sinx + tanx] / [cosx +1] = tanx

Answer 1

I just got done with thi stuff and these are the formulas that helped me with alot.
tan(angle)=opposite/adjacent

coa(angle)=adjacent/hypotenuse

sin(angle)=opposite/hypotenuse

Is this what your asking for?

Answer 2

that's sort of a tricky one,

[sinx + tanx] / [cosx +1] = tanx
LS = (sinx + tanx)/(cosx+1) [(cosx-1)/cosx-1)]
= (sinxcosx - sinx + sinx - sinx/cosx)/(cos^2x - 1)
= [ (sinxcos^2x - sinx)/cosx]/(cos^2x - 1)
= sinx[cos^2x - 1)/cosx] / (cos^2x - 1)
= sinx/cosx
= tanx
= RS